传送门:
思路将关系 a [ i ] < = a [ i − 1 ] a[i]n>>m; for(int i=1;i>a[i]; for(int i=1;i=a[i-1])); for(int i=1;i>op; if(op == 1) { int k,x; cin>>k>>x; if((a[k]>=a[k-1])>(x>=a[k-1])) modify(k,-1); if((a[k]>=a[k-1])=a[k-1])) modify(k,1); if((a[k]>=a[k+1])>(x>=a[k+1])) modify(k+1,1); if((a[k]>=a[k+1])=a[k+1])) modify(k+1,-1); a[k]=x; }else { int l,r; cin>>l>>r; if(query(l,r) == r-l) cout
